Influence of raster angle on mechanical properties for FDM 3D-printed PLA polymer

In the present work, the influence of raster angle (0°, 45°, and 90°) on the mechanical properties of 3D-printed polylactic acid has been investigated. Tensile, hardness, and impact tests were conducted for the same. Furthermore, dynamic mechanical analysis has also been conducted. The results revealed that the mechanical properties of specimens printed at a 0° raster angle are better than the specimens printed at other raster angles. Furthermore, dynamic mechanical analysis exposed that the storage modulus is higher for the specimen printed at a 0° raster angle, and the loss tangent (tan δ) is higher for the specimen printed at a 90° raster angle. The yield strength of 45° and 90° raster angles was 7.12% and 19.74% less than the 0° raster angle, respectively. The ultimate tensile strength of 45° and 90° raster angles was 6.46% and 19.10% less than the 0° raster angle, respectively. The 0° printed specimen exhibited maximum impact strength (45 kJ/m²), hardness (17.45 HV), and flexural strength (64.77 MPa), followed by 45° and 90° specimens. Furthermore, the fracture strain was less than 6% for 45° and 90° raster angles at the comparison of 0° raster angle.